Stained glass windows, and other glass artifacts, traditionally have been manufactured by cutting panes of different colored glass into sections having a desired shape and size, and assembling these sections of glass into a composite to form a design or picture. Traditionally, a lead based solder has been applied to the adjoining edges of the sections of glass to hold the sections together. However, since solder does not adhere well to glass, an intermediate layer formed of another substance is required. Copper is the material most often used in recent times, since, in thin strips, it is maleable, and since solder adheres well to the surface of the copper.
In making stained glass windows and artifacts, a strip of copper is applied to each glass edge and the edges of the strips are folded over onto the outer surfaces of the glass. Starting in the late 1800's, these copper strips were secured to the edges of the glass sections using beeswax. After pressure sensitive adhesives were developed, the copper strips were provided with a layer of adhesive along one side for application to the glass edges. After the glass sections have been placed in the desired relationship to one another, molten solder is applied uniformly along the adjoining edges of the glass sections, covering the exposed edges of the copper strips disposed on the outer surfaces of the glass sections and the spaces between adjoining edges of the sections. A bead of solder is formed bridging the spaces between adjoining edges to attach each section of glass to the sections immediately adjoining it.
The use of copper strips for stained glass windows and artifacts is often found not to be aesthetically pleasing. In the first place, the glass does not have an authentic, antique look. Although the solder bead assumes a somewhat darkened color with time, the copper strip retains its color, since it is sealed between the solder bead and the glass. Since the adhesive used to bond the copper strip to the glass is generally transparent, if the window or artifact is viewed at a slight angle, the copper color on the backside of the copper strip is readily visible around the edges of each section of glass. It is readily apparent by looking at such windows from an angle that copper was used in their manufacture, particularly since the copper color clashes with the darker color of the aged solder bead. Secondly, this copper color and the reflected light can detract from the design and the colored effect of the glass. Thirdly, the copper surface readily reflects light and this reflected light is both annoying and detracting from the design of the window or artifact.
An object of this invention is to provide an adhesive copper strip which can be used for producing stained glass windows in which the copper is not visible after application to the window.
Another object of the present invention is to produce an adhesive copper strip whose adhesive side has a blackened coloration.